Building a 600HP Big-Block for $4000

Our Blue Collar 454 first appeared in the July '12 issue and consisted of a stock-bore block and rotating assembly from a late-'70s Suburban and a pair of 049-casting oval-port cylinder heads (rebuildable cores can be found on eBay for about $100–$150 apiece). Though the parts were incredibly grimy, the block cleaned up well and showed very little wear in the cylinders. JMS Racing Engines in El Monte, California, rebuilt the heads for us while we reconditioned the block and stock rotating assembly at home. With a tiny RV cam, this combination made 408 hp and 511 lb-ft of torque for the paltry sum of $1,900 carb-to-oil pan (including the machine shop cost!). We were so cheap, we ran out of engine paint and didn't finish painting the heads. All the details can be found in the July '12 issue.

We did a couple more builds with it, adding forged pistons and a tunnel ram, and making 594 hp (naturally aspirated) and 800 hp on nitrous before destroying one of the main bearings. We've brought the Blue Collar 454 back this month to try to duplicate that feat, but without the pricey tunnel-ram/dual-quad setup. We achieved that goal—exceeding it by a few ponies, in fact—and in the process, we laid a good foundation from which to proceed. Our plans are to fully maximize the potential of these lowly cast-iron cylinder heads before seeking an aftermarket solution.

On the Dyno114-octane Rockett Brand gasoline, 36 degrees total timing

RPM

TQ

HP

3,600

443.1

303.7

3,700

447.7

315.4

3,800

456

329.9

3,900

463.6

344.3

4,000

471.3

359

4,100

478.5

373.5

4,200

487.1

389.5

4,300

495.4

405.6

4,400

503.9

422.1

4,500

509.1

436.2

4,600

512.1

448.6

4,700

513.4

459.5

4,800

514

469.7

4,900

513.5

479.1

5,000

512.2

487.6

5,100

511.1

496.3

5,200

511.8

506.7

5,300

513.7

518.4

5,400

515.6

530.2

5,500

516.8

541.2

5,600

517

551.2

5,700

516

560.1

5,800

514.1

567.7

5,900

511.7

574.8

6,000

509.2

581.8

6,100

506.9

588.7

6,200

504.4

595.4

6,300

501.7

601.8

6,400

498

606.8

6,500

493.7

611

6,600

488.2

613.4

6,700

480.1

612.5

91-octane Rockett Brand gasoline, 28 degrees total timing

RPM

TQ

HP

3,500

391.3

260.8

3,600

394.3

270.2

3,700

404.9

285.2

3,800

417.8

302.3

3,900

427

317.1

4,000

435.2

331.5

4,100

442.1

345.1

4,200

450.8

360.5

4,300

460.5

377

4,400

469

392.9

4,500

475.3

407.2

4,600

480.2

420.5

4,700

483.1

432.3

4,800

484.5

442.8

4,900

484.3

451.9

5,000

483.7

460.5

5,100

482.6

468.6

5,200

481.3

476.5

5,300

480.4

484.8

5,400

480.2

493.7

5,500

481.5

504.3

5,600

482.4

514.4

5,700

481.7

522.8

5,800

479.2

529.2

5,900

476.4

535.1

6,000

474

541.5

6,100

471.9

548.1

6,200

469.5

554.2

6,300

465.5

558.4

6,400

460.6

561.2

6,500

455.9

564.3

6,600

450.7

566.4

6,700

444.6

567.2

2/17

Watching Star Trek and assembling big blocks.

3/17

Stepping into the Wayback machine, here's what the engine looked like when we first took possession. It's difficult to believe something this gross could make decent power.

4/17

Based on previous building experience, we decided to try a bigger cam and slightly bigger intake valves—going from 2.18-inch to 2.250-inch, the same size that performance rectangle-port heads use. The exhaust valves remain 1.88-inch, as used in the last test. We installed Comp Cams' Sportsman stainless steel valves this time, with an 11⁄32 diameter, which is slightly thinner than stock.

5/17

We also knew the cam we wanted to use would make peak power somewhere above 6,500 rpm, so we opted for Comp's tool steel valvespring retainers, shown in the foreground. They weigh about 33 percent less than chromoly retainers and are within 4 grams of titanium, yet cost about $100 less. Shedding some weight from the retainers allowed us to rev the engine a little higher and offers better valve control at high rpm.

6/17

Fred De La Cruz at HPS Automotive Machining did some basic clean up in the exhaust ports, where big-block heads can use more airflow.

7/17

Upon disassembly of the last iteration of Blue Collar, we discovered the spark plugs had been hitting the piston domes in all the cylinders. We were lucky that no damage was done, but this shows the importance of not only selecting the correct heat range spark plug but also the correct reach into the combustion chamber.

8/17

We used a carbide cutter to grind the spark-plug gouge out of the pistons. We also took the time to grind all the sharp edges off the piston domes. We didn't remove much material, just rounded off the sharp edges.

9/17

We chose a solid flat-tappet cam from Comp with 270/280 degrees duration at 0.050-inch tappet lift and 0.650-inch valve lift with stock ratio rocker arms. Because of the increased lift and duration from the previous build, we needed to check piston to valve clearance again, so we temporarily reinstalled the cam.

Test Day
At Westech, we installed an Edelbrock Victor Jr. intake manifold and MSD distributor, filled the crankcase with 6 quarts of Comp's engine break-in oil, fired the engine, and ran it through a break-in cycle. Even with relatively high valvespring pressure (150 lb-in installed height/350 lb-in open), our flat-tappet cam broke in fine. With the right assembly lube, break-in oil, and a proper break-in procedure, there's no need to fear using a flat-tappet cam.

Westech's Steve Brulé used 114-octane Rockett Brand gasoline for break-in and the first several dyno pulls, and our engine surprised us with a peak horsepower number of 613 at 6,600 rpm. Brulé eased off the throttle at what appeared to be the onset of valve float. With lighter valvetrain components and/or more spring pressure, we think this engine will continue to make power up to 7,000 rpm—something we will experiment with soon.

10/17

Brulé then surprised us even more by reducing the total timing to 28 degrees and running the engine on Rockett 91-octane gasoline. Blue Collar cranked out 567 hp with absolutely no indication of detonation.

*This engine actually costs a bit more than it needs to because we are using parts left over from some roller cam R&D tests. The good news is that you can build it for less and make the same amount of power. According to Comp's web page for our cam grind, the company recommends less-expensive rocker arms, pushrods, and timing set than the ones we used. You can also save some money using Fel-Pro's composite head gaskets, which cost about half the cost of MLS gaskets. We still recommend the tool steel retainers, however. Recalculating our total with Comp's recommendation and composite gaskets comes to a grand total of $3,766.05—an awesome price for a ready-to-run, 600hp, big-block Chevy, especially one you could drive to the track. If you can spend more, the added insurance of our Ultra Gold rocker arms and boost-ready MLS gaskets mean you will have room to grow if you want to squeeze more power out of this combination, which we plan to do soon.

11/17

Parts List

Description

P/N

Source

Price

Used 454

NA

Hot Rod Magazine

$300.00

Sealed Power engine rebuild kit

CSMHP771-300

Summit Racing

789.97

MLS head gaskets

Fel-1071

Fel-Pro

151.94

Cylinder head bolts

ARP-135-3601

ARP

82.66

Main cap bolt kit

ARP-135-5002

ARP

41.72

Connecting rod bolts

ARP-135-6401

ARP

68.96

7/16-inch rocker studs

ARP-135-7102

ARP

47.98

Comp solid flat-tappet cam

CCA-11-406-5

Summit Racing

191.99

Performance Series solid lifters

CCA-2900-16

COMP

99.97

Intake valves: 2.250-inch

CCA-6022-8

Comp

99.97

Exhaust valves: 1.880-inch

CCA-6023-8

Comp

89.97

Valvespring locators

CCA-4759-16

Comp

34.97

Valvesprings

CCA-954-16

Comp

129.97

Valvespring retainers

CCA-1732-16

Comp

149.97

Viton valve seals

CCA-517-16

Comp

17.97

Roller rocker arms

CCA-17021-16

Comp

299.97

Valve locks

CCA-611-16

Comp

21.97

Pushrod kit

CCA-7154-16

Comp

195.97

Timing set

CCA-7110

Comp

103.97

Water pump, aluminum

SUM-310125

Summit Racing

139.97

Intake manifold

EDL-2904

Edelbrock

279.97

950 HP carburetor

HLY-0-82951

Holley

699.99

Engine paint

NA

O'Reilly Auto Parts

8.99

RTV sealer

VER-99839

O'Reilly Auto Parts

5.49

Sealed Power Assembly lube

SLP-55-400

Summit Racing

4.25

Comp Cams Engine Break-In Oil, case

CCA-1590

Comp Cams

59.95

Oil filter

PH-30

Fram

4.59

Spark plugs

NGK R5673-9

NAPA

27.92

Total as Tested

4,061.01

By the Numbers

Blue Collar 454:

Bore

4.280 inch

Stroke

4.00 inch

Cylinder head volume

120 cc

Piston dome volume

49 cc

Deck clearance

0.009 inch

Gasket compressed thickness

0.051 inch

Gasket bore diameter

4.380

Compression ratio

12.32:1

Final displacement

460 ci

12/17

We dropped a cylinder head on the driver side without a gasket and cycled the engine through a couple rotations of the crankshaft with the valves set at zero lash and a pair of checking springs. The exhaust valve left no impression on the CC-approved Silly Putty we smooshed on top of the piston. The intake valve showed 0.070-inch clearance, which, combined with our 0.041-inch compressed-thickness head gasket, is plenty of clearance.

13/17

With the knowledge that our clearances were in spec, we cleaned the deck of the block and the tops of the pistons with a Scotch-Brite pad and wiped everything with brake cleaner, then automatic transmission fluid in preparation for final assembly.

14/17

While we had the Silly Putty out, we also checked the oil pan–to–pickup clearance, which was acceptable at about 3⁄4 inch.

15/17

We are planning to hit this engine with about a 200 shot of nitrous in a later test, so we opted for Fel-Pro's MLS head gaskets. Naturally aspirated builds can save a few bucks by using standard gaskets. We are using Comp's two-piece timing cover for this build because this engine has recently been used to test several of its new cam designs. We left it out of the parts list because the stock cover would work just fine here. We actually would have put the stock one back on, but we couldn't find the fasteners.

16/17

We installed the cam "straight up" (with no advance or retard) and verified the intake lobe centerline, which was spot on with Comp's spec of 114 degrees after TDC. The intake and exhaust opening and closing events were also perfect. Note that we haven't installed the poly locks on the rocker arms yet. It's easier to rotate the crankshaft without the load of the valvesprings.

17/17

We assembled the rest of the valvetrain using plenty of assembly lube on the lifters, rocker arms, and pushrods and set the valve lash to 0.028-inch intake and 0.030-inch exhaust, per Comp's specs.